Re: [Kimchi-devel] [v1 1/1] Migrate virtual machines

于 2014年11月04日 03:29, Aline Manera 写道: > > On 11/03/2014 12:12 PM, Simon Jin wrote: >> Signed-off-by: Simon Jin <simonjin(a)linux.vnet.ibm.com&gt; >> --- >> docs/API.md | 3 +- >> src/kimchi/control/vms.py | 1 + >> src/kimchi/exception.py | 3 + >> src/kimchi/i18n.py | 11 ++++ >> src/kimchi/model/vms.py | 138 >> ++++++++++++++++++++++++++++++++++++++++++++++ >> 5 files changed, 155 insertions(+), 1 deletion(-) >> >> diff --git a/docs/API.md b/docs/API.md >> index 92fbbd5..28dbc6e 100644 >> --- a/docs/API.md >> +++ b/docs/API.md >> @@ -132,7 +132,8 @@ the following general conventions: >> It emulates the power reset button on a machine. Note that there is a >> risk of data loss caused by reset without the guest OS shutdown. >> * connect: Prepare the connection for spice or vnc >> - >> +* migrate: Migrate a VM to remote server, only support live mode >> with out block migration. >> + > > As the "migrate" operation will require some data like host, username > and password, you need to describe them too. > You can see the POST request to have an idea on how to do it. > OK >> ### Sub-resource: Virtual Machine Screenshot >> >> **URI:** /vms/*:name*/screenshot >> diff --git a/src/kimchi/control/vms.py b/src/kimchi/control/vms.py >> index 88d8a81..64b88ad 100644 >> --- a/src/kimchi/control/vms.py >> +++ b/src/kimchi/control/vms.py >> @@ -42,6 +42,7 @@ class VM(Resource): >> for ident, node in sub_nodes.items(): >> setattr(self, ident, node(model, self.ident)) >> self.start = self.generate_action_handler('start') > >> + self.migrate = self.generate_action_handler('migrate', >> 'remoteHost', 'user', 'passwd') > > Migration will take some time to complete so it is better to use > self.generate_action_handler_task() which will expect a Task instead > of a new resource. > Also self.generate_action_handler*() accepts only one parameter which > is the action name. > > Example: self.generate_action_handler_task('migrate') > OK. > All the other parameters will come on a dict when hits the model code. > So on model/vms.py you will have; > > def migrate(self, name, params): > > And "params" will have all the information you need: host, username > and password. > action_args should be a list/tuple, so the code should be: self.migrate = self.generate_action_handler('migrate', ['remoteHost', 'user', 'passwd']), other example is in src/kimchi/control/storagevolumes.py: self.resize = self.generate_action_handler('resize', ['size']) def generate_action_handler(self, action_name, action_args=None): def wrapper(*args, **kwargs): validate_method(('POST'), self.role_key, self.admin_methods) try: self.lookup() if not self.is_authorized(): raise UnauthorizedError('KCHAPI0009E') model_args = list(self.model_args) if action_args is not None: request = parse_request() model_args.extend(request[key] for key in action_args) fn = getattr(self.model, model_fn(self, action_name)) ident = fn(*model_args)

>> self.poweroff = self.generate_action_handler('poweroff') >> self.shutdown = self.generate_action_handler('shutdown') >> self.reset = self.generate_action_handler('reset') >> diff --git a/src/kimchi/exception.py b/src/kimchi/exception.py >> index 039152a..732b3ee 100644 >> --- a/src/kimchi/exception.py >> +++ b/src/kimchi/exception.py >> @@ -100,3 +100,6 @@ class TimeoutExpired(KimchiException): >> >> class UnauthorizedError(KimchiException): >> pass > >> + >> +class MigrationError(KimchiException): >> + pass > > You don't need to create a new type of error. > You can use OperationFailed > OK >> \ No newline at end of file >> diff --git a/src/kimchi/i18n.py b/src/kimchi/i18n.py >> index 75fb076..2fd1073 100644 >> --- a/src/kimchi/i18n.py >> +++ b/src/kimchi/i18n.py >> @@ -101,6 +101,17 @@ messages = { >> "KCHVM0030E": _("Unable to get access metadata of virtual machine >> %(name)s. Details: %(err)s"), >> "KCHVM0031E": _("The guest console password must be a string."), >> "KCHVM0032E": _("The life time for the guest console password must >> be a number."), >> + "KCHVM0033E": _("Can't migrate to localhost."), > >> + "KCHVM0034E": _("Can't migrate vm %(name)s on Hypervisor arch >> %(srcarch)s.to a different Hypervisor arch %(destarch)s."), X86 --> PPC >> + "KCHVM0035E": _("Can't migrate from %(srchyp)s to a different >> Hypervisor type %(desthyp)s."), > Qemu/kvm --> Xen > What is the difference between those 2 messages? > >> + "KCHVM0036E": _("Can't migrate vm %(name)s,which is already in >> migrating state."), >> + "KCHVM0037E": _("Can't migrate vm %(name)s,which isn't in running >> state."), > > Does it mean I can not migrate a powered off vm? > a powered off vm can be migrated with --offline, will add this support in v2. >> + "KCHVM0038E": _("Can't migrate vm %(name)s, vm has passthrough >> device %(hostdevs)s."), >> + "KCHVM0039E": _("Can't migrate vm %(name)s, vm already exist on >> destination server %(remoteHost)s."), >> + "KCHVM0040E": _("Failed Migrate vm %(name)s due error: %(err)s"), >> + "KCHVM0041E": _("Failed resume vm %(name)s from migration recover. >> Details: %(err)s"), >> + "KCHVM0042E": _("Failed destory vm %(name)s from migration >> recover. Details: %(err)s"), >> + "KCHVM0043E": _("Failed disconnect %(remoteuri)s when finish >> migrate vm %(name)s. Details: %(err)s"), >> >> "KCHVMHDEV0001E": _("VM %(vmid)s does not contain directly assigned >> host device %(dev_name)s."), >> "KCHVMHDEV0002E": _("The host device %(dev_name)s is not allowed to >> directly assign to VM."), >> diff --git a/src/kimchi/model/vms.py b/src/kimchi/model/vms.py >> index 1089464..1c4eef0 100644 >> --- a/src/kimchi/model/vms.py >> +++ b/src/kimchi/model/vms.py >> @@ -44,6 +44,11 @@ from kimchi.utils import import_class, >> kimchi_log, run_setfacl_set_attr >> from kimchi.utils import template_name_from_uri >> from kimchi.xmlutils.utils import xpath_get_text, xml_item_update > >> +from kimchi.model.libvirtconnection import LibvirtConnection >> +from kimchi.utils import add_task >> +from kimchi.model.templates import TemplateModel >> +from kimchi.model.vmhostdevs import VMHostDevsModel >> +from kimchi.exception import MigrationError > > The imports must be in alphabetic order. > ok >> DOM_STATE_MAP = {0: 'nostate', >> 1: 'running', >> @@ -507,6 +512,139 @@ class VMModel(object): >> except libvirt.libvirtError as e: >> raise OperationFailed("KCHVM0019E", >> {'name': name, 'err': e.get_error_message()}) >> + >> + def _preCheck(self, name, destConn, remoteHost): >> + kimchi_log.debug('precheck migrate %s' % name) >> + >> + if remoteHost == 'localhost' or '127.0.0.1': >> + kimchi_log.debug('vm %s is not in running, only running vm can be >> migrated' % name) >> + raise MigrationError("KCHVM00033E", {'name': name, >> + 'remoteHost': remoteHost}) >> + >> + >> + if self.conn.get().getInfo()[0] != destConn.getInfo()[0]: >> + kimchi_log.debug('vm %s can not migrate to different arch server.' >> % (name, destConn.getInfo()[0])) >> + raise MigrationError("KCHVM00034E", {'name': name, >> + 'srcarch': self.conn.get().getType(), >> + 'destarch': self.destConn.getType()}) >> + >> + if self.conn.get().getType() != self.destConn.getType(): >> + kimchi_log.debug('vm %s can not migrate to a different hypervisor' >> % name) >> + raise MigrationError("KCHVM00035E", {'name': self.name, >> + 'srchyp':self.conn.get().getType(), >> + 'desthyp': self.destConn.getType()}) >> + >> + dom = self.vm.get_vm(self.name, self.conn) >> + >> + state = DOM_STATE_MAP[dom.info()[0]] >> + if state == 'migrating': #TODO how to set vm as migrating status ? >> + kimchi_log.debug('vm is already in migrating %s' % name) >> + raise MigrationError("KCHVM00036E", {'name': self.name,}) > >> + elif state != 'running': >> + kimchi_log.debug('vm %s is not in running, only running vm can be >> migrated' % name) >> + raise MigrationError("KCHVM00037E", {'name': self.name}) >> + > > Why can't I do cold migration? > >> + #check if there is any passthrough devices belong to this vm >> + vmhostdevs = VMHostDevsModel(conn = self.conn) >> + hostdevs = vmhostdevs.get_list(self.name) >> + if hostdevs: >> + raise MigrationError("KCHVM00038E", {'name' : name, >> + 'hostdevs': hostdevs}) >> + >> + if self.get_vm(name, destConn): >> + kimchi_log.debug('migrate vm %s already exist on %s' % (name, >> destConn.getURI())) >> + raise MigrationError("KCHVM00039E", {'name' : name, >> + 'remoteHost': remoteHost}) >> + >> + >> + def _getRemoteConn(self, remoteHost, user): >> + #open destination connect to migrate >> + transport = 'ssh' >> + duri = 'qemu+%s://%s@%s/system' % (transport, >> + user,remoteHost) >> + >> + conn = LibvirtConnection(duri) >> + destConn = conn.get() >> + return destConn >> + >> + def _preMigrate(self, name): >> + #can't update VM while in Migration source/destination >> + kimchi_log.debug('prepare migrate %s' % name) >> + dom = self.get_vm(name, self.conn) >> + dom.migrateSetMaxDowntime(0) >> + >> + >> + def _do_migrate(self, name, destConn, remoteHost, cb): >> + >> + cb('starting a migration') >> + kimchi_log.debug('migrate %s start' % name) >> + >> + flag = 0 >> + flag |= (libvirt.VIR_MIGRATE_LIVE | >> + libvirt.VIR_MIGRATE_PEER2PEER | >> + libvirt.VIR_MIGRATE_TUNNELLED) >> + #libvirt.VIR_MIGRATE_ABORT_ON_ERROR) >> + >> + try: >> + self.vm.migrate(destConn, None, None,flag, >> + None, 0) >> + except libvirt.libvirtError as e: >> + kimchi_log.error('migrate %s to %s failed' % (name, >> + remoteHost)) >> + self._recover(cb) >> + raise MigrationError('KCHPOOL0040E', {'err': e.message, >> + 'name': name}) >> + finally: >> + self._finish(name, destConn, cb) >> + >> + def migrate(self, name, remoteHost, user, passwd ): >> + destconn = self._getRemoteConn(remoteHost, user) >> + >> + self._preCheck(name, destconn, remoteHost) >> + self._preMigrate(name) >> + >> + task_id = add_task('/vms/%s/migrate' % name, self._do_migrate, >> self.objstore, >> + {'name' : name, 'destconn': destconn, 'remoteHost': remoteHost}) >> + >> + # Record vm migrate task for future querying >> + try: >> + with self.objstore as session: >> + session.store('migrate', self.name, task_id) >> + return task_id >> + except Exception as e: >> + raise MigrationError('KCHPOOL0037E', {'err': e.message}) >> + >> + def _recover(self, name, destconn, cb): >> + #recover >> + cb('recover from a failed migration',False) >> + kimchi_log.debug('recover from a failed migrate %s' % name) >> + dom = self.get_vm(name, self.conn) >> + state = DOM_STATE_MAP[dom.info()[0]] >> + if state == 'paused': > > Does it mean the VM will be paused during migration? will delete this. -Simon > My concern is because Kimchi does not deal well with paused state. > >> + try: >> + dom.resume() >> + except libvirt.libvirtError as e: >> + raise OperationFailed("KCHVM0041E", >> + {'name': name, 'err': e.get_error_message()}) >> + try: >> + destvm = self.get_vm(name, destconn) >> + destvm.destroy() >> + kimchi_log.error("destory migrate vm on destination server") >> + #destory and undefine >> + except libvirt.libvirtError as e: >> + raise MigrationError('KCHPOOL0042E', {'name' : name, >> + 'err': e.message}) >> + >> + def _finish(self, name, destConnc, cb): >> + kimchi_log.debug('finished migrate %s' % name) >> + try: >> + destConnc.close() >> + except libvirt.libvirtError as e: >> + raise MigrationError('KCHPOOL0043E', {'name' : name, >> + 'remoteuri' : destConnc.getURI(), >> + 'err': e.message}) >> + finally: >> + cb('Migrate finished', True) >> >> def poweroff(self, name): >> dom = self.get_vm(name, self.conn) >